1bd2d0210STheodore Ts'o /* 2bd2d0210STheodore Ts'o * linux/fs/ext4/page-io.c 3bd2d0210STheodore Ts'o * 4bd2d0210STheodore Ts'o * This contains the new page_io functions for ext4 5bd2d0210STheodore Ts'o * 6bd2d0210STheodore Ts'o * Written by Theodore Ts'o, 2010. 7bd2d0210STheodore Ts'o */ 8bd2d0210STheodore Ts'o 9bd2d0210STheodore Ts'o #include <linux/fs.h> 10bd2d0210STheodore Ts'o #include <linux/time.h> 11bd2d0210STheodore Ts'o #include <linux/highuid.h> 12bd2d0210STheodore Ts'o #include <linux/pagemap.h> 13bd2d0210STheodore Ts'o #include <linux/quotaops.h> 14bd2d0210STheodore Ts'o #include <linux/string.h> 15bd2d0210STheodore Ts'o #include <linux/buffer_head.h> 16bd2d0210STheodore Ts'o #include <linux/writeback.h> 17bd2d0210STheodore Ts'o #include <linux/pagevec.h> 18bd2d0210STheodore Ts'o #include <linux/mpage.h> 19bd2d0210STheodore Ts'o #include <linux/namei.h> 20bd2d0210STheodore Ts'o #include <linux/uio.h> 21bd2d0210STheodore Ts'o #include <linux/bio.h> 22bd2d0210STheodore Ts'o #include <linux/workqueue.h> 23bd2d0210STheodore Ts'o #include <linux/kernel.h> 24bd2d0210STheodore Ts'o #include <linux/slab.h> 251ae48a63SJan Kara #include <linux/mm.h> 26c9af28fdSTheodore Ts'o #include <linux/backing-dev.h> 27bd2d0210STheodore Ts'o 28bd2d0210STheodore Ts'o #include "ext4_jbd2.h" 29bd2d0210STheodore Ts'o #include "xattr.h" 30bd2d0210STheodore Ts'o #include "acl.h" 31bd2d0210STheodore Ts'o 320058f965SJan Kara static struct kmem_cache *io_end_cachep; 33bd2d0210STheodore Ts'o 345dabfc78STheodore Ts'o int __init ext4_init_pageio(void) 35bd2d0210STheodore Ts'o { 36bd2d0210STheodore Ts'o io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT); 370058f965SJan Kara if (io_end_cachep == NULL) 38bd2d0210STheodore Ts'o return -ENOMEM; 39bd2d0210STheodore Ts'o return 0; 40bd2d0210STheodore Ts'o } 41bd2d0210STheodore Ts'o 425dabfc78STheodore Ts'o void ext4_exit_pageio(void) 43bd2d0210STheodore Ts'o { 44bd2d0210STheodore Ts'o kmem_cache_destroy(io_end_cachep); 45bd2d0210STheodore Ts'o } 46bd2d0210STheodore Ts'o 471ada47d9STheodore Ts'o /* 48b0857d30SJan Kara * Print an buffer I/O error compatible with the fs/buffer.c. This 49b0857d30SJan Kara * provides compatibility with dmesg scrapers that look for a specific 50b0857d30SJan Kara * buffer I/O error message. We really need a unified error reporting 51b0857d30SJan Kara * structure to userspace ala Digital Unix's uerf system, but it's 52b0857d30SJan Kara * probably not going to happen in my lifetime, due to LKML politics... 53b0857d30SJan Kara */ 54b0857d30SJan Kara static void buffer_io_error(struct buffer_head *bh) 55b0857d30SJan Kara { 56a1c6f057SDmitry Monakhov printk_ratelimited(KERN_ERR "Buffer I/O error on device %pg, logical block %llu\n", 57a1c6f057SDmitry Monakhov bh->b_bdev, 58b0857d30SJan Kara (unsigned long long)bh->b_blocknr); 59b0857d30SJan Kara } 60b0857d30SJan Kara 61b0857d30SJan Kara static void ext4_finish_bio(struct bio *bio) 62b0857d30SJan Kara { 63b0857d30SJan Kara int i; 642c30c71bSKent Overstreet struct bio_vec *bvec; 65b0857d30SJan Kara 662c30c71bSKent Overstreet bio_for_each_segment_all(bvec, bio, i) { 67b0857d30SJan Kara struct page *page = bvec->bv_page; 682058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 692058f83aSMichael Halcrow struct page *data_page = NULL; 702058f83aSMichael Halcrow struct ext4_crypto_ctx *ctx = NULL; 712058f83aSMichael Halcrow #endif 72b0857d30SJan Kara struct buffer_head *bh, *head; 73b0857d30SJan Kara unsigned bio_start = bvec->bv_offset; 74b0857d30SJan Kara unsigned bio_end = bio_start + bvec->bv_len; 75b0857d30SJan Kara unsigned under_io = 0; 76b0857d30SJan Kara unsigned long flags; 77b0857d30SJan Kara 78b0857d30SJan Kara if (!page) 79b0857d30SJan Kara continue; 80b0857d30SJan Kara 812058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 822058f83aSMichael Halcrow if (!page->mapping) { 832058f83aSMichael Halcrow /* The bounce data pages are unmapped. */ 842058f83aSMichael Halcrow data_page = page; 852058f83aSMichael Halcrow ctx = (struct ext4_crypto_ctx *)page_private(data_page); 86614def70STheodore Ts'o page = ctx->w.control_page; 872058f83aSMichael Halcrow } 882058f83aSMichael Halcrow #endif 892058f83aSMichael Halcrow 904246a0b6SChristoph Hellwig if (bio->bi_error) { 91b0857d30SJan Kara SetPageError(page); 92b0857d30SJan Kara set_bit(AS_EIO, &page->mapping->flags); 93b0857d30SJan Kara } 94b0857d30SJan Kara bh = head = page_buffers(page); 95b0857d30SJan Kara /* 96b0857d30SJan Kara * We check all buffers in the page under BH_Uptodate_Lock 97b0857d30SJan Kara * to avoid races with other end io clearing async_write flags 98b0857d30SJan Kara */ 99b0857d30SJan Kara local_irq_save(flags); 100b0857d30SJan Kara bit_spin_lock(BH_Uptodate_Lock, &head->b_state); 101b0857d30SJan Kara do { 102b0857d30SJan Kara if (bh_offset(bh) < bio_start || 103b0857d30SJan Kara bh_offset(bh) + bh->b_size > bio_end) { 104b0857d30SJan Kara if (buffer_async_write(bh)) 105b0857d30SJan Kara under_io++; 106b0857d30SJan Kara continue; 107b0857d30SJan Kara } 108b0857d30SJan Kara clear_buffer_async_write(bh); 1094246a0b6SChristoph Hellwig if (bio->bi_error) 110b0857d30SJan Kara buffer_io_error(bh); 111b0857d30SJan Kara } while ((bh = bh->b_this_page) != head); 112b0857d30SJan Kara bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); 113b0857d30SJan Kara local_irq_restore(flags); 1142058f83aSMichael Halcrow if (!under_io) { 1152058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 1162058f83aSMichael Halcrow if (ctx) 1172058f83aSMichael Halcrow ext4_restore_control_page(data_page); 1182058f83aSMichael Halcrow #endif 119b0857d30SJan Kara end_page_writeback(page); 120b0857d30SJan Kara } 121b0857d30SJan Kara } 1222058f83aSMichael Halcrow } 123b0857d30SJan Kara 12497a851edSJan Kara static void ext4_release_io_end(ext4_io_end_t *io_end) 125bd2d0210STheodore Ts'o { 126b0857d30SJan Kara struct bio *bio, *next_bio; 127b0857d30SJan Kara 12897a851edSJan Kara BUG_ON(!list_empty(&io_end->list)); 12997a851edSJan Kara BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); 1306b523df4SJan Kara WARN_ON(io_end->handle); 131bd2d0210STheodore Ts'o 132b0857d30SJan Kara for (bio = io_end->bio; bio; bio = next_bio) { 133b0857d30SJan Kara next_bio = bio->bi_private; 134b0857d30SJan Kara ext4_finish_bio(bio); 135b0857d30SJan Kara bio_put(bio); 136b0857d30SJan Kara } 13797a851edSJan Kara kmem_cache_free(io_end_cachep, io_end); 13897a851edSJan Kara } 13997a851edSJan Kara 140a115f749SJan Kara /* 141a115f749SJan Kara * Check a range of space and convert unwritten extents to written. Note that 142a115f749SJan Kara * we are protected from truncate touching same part of extent tree by the 143a115f749SJan Kara * fact that truncate code waits for all DIO to finish (thus exclusion from 144a115f749SJan Kara * direct IO is achieved) and also waits for PageWriteback bits. Thus we 145a115f749SJan Kara * cannot get to ext4_ext_truncate() before all IOs overlapping that range are 146a115f749SJan Kara * completed (happens from ext4_free_ioend()). 147a115f749SJan Kara */ 14828a535f9SDmitry Monakhov static int ext4_end_io(ext4_io_end_t *io) 149bd2d0210STheodore Ts'o { 150bd2d0210STheodore Ts'o struct inode *inode = io->inode; 151bd2d0210STheodore Ts'o loff_t offset = io->offset; 152bd2d0210STheodore Ts'o ssize_t size = io->size; 1536b523df4SJan Kara handle_t *handle = io->handle; 154bd2d0210STheodore Ts'o int ret = 0; 155bd2d0210STheodore Ts'o 156bd2d0210STheodore Ts'o ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," 157bd2d0210STheodore Ts'o "list->prev 0x%p\n", 158bd2d0210STheodore Ts'o io, inode->i_ino, io->list.next, io->list.prev); 159bd2d0210STheodore Ts'o 1606b523df4SJan Kara io->handle = NULL; /* Following call will use up the handle */ 1616b523df4SJan Kara ret = ext4_convert_unwritten_extents(handle, inode, offset, size); 162bd2d0210STheodore Ts'o if (ret < 0) { 163b82e384cSTheodore Ts'o ext4_msg(inode->i_sb, KERN_EMERG, 164b82e384cSTheodore Ts'o "failed to convert unwritten extents to written " 165b82e384cSTheodore Ts'o "extents -- potential data loss! " 166b82e384cSTheodore Ts'o "(inode %lu, offset %llu, size %zd, error %d)", 167b82e384cSTheodore Ts'o inode->i_ino, offset, size, ret); 168bd2d0210STheodore Ts'o } 16997a851edSJan Kara ext4_clear_io_unwritten_flag(io); 17097a851edSJan Kara ext4_release_io_end(io); 171bd2d0210STheodore Ts'o return ret; 172bd2d0210STheodore Ts'o } 173bd2d0210STheodore Ts'o 1742e8fa54eSJan Kara static void dump_completed_IO(struct inode *inode, struct list_head *head) 17528a535f9SDmitry Monakhov { 17628a535f9SDmitry Monakhov #ifdef EXT4FS_DEBUG 17728a535f9SDmitry Monakhov struct list_head *cur, *before, *after; 17828a535f9SDmitry Monakhov ext4_io_end_t *io, *io0, *io1; 17928a535f9SDmitry Monakhov 1802e8fa54eSJan Kara if (list_empty(head)) 18128a535f9SDmitry Monakhov return; 18228a535f9SDmitry Monakhov 1832e8fa54eSJan Kara ext4_debug("Dump inode %lu completed io list\n", inode->i_ino); 1842e8fa54eSJan Kara list_for_each_entry(io, head, list) { 18528a535f9SDmitry Monakhov cur = &io->list; 18628a535f9SDmitry Monakhov before = cur->prev; 18728a535f9SDmitry Monakhov io0 = container_of(before, ext4_io_end_t, list); 18828a535f9SDmitry Monakhov after = cur->next; 18928a535f9SDmitry Monakhov io1 = container_of(after, ext4_io_end_t, list); 19028a535f9SDmitry Monakhov 19128a535f9SDmitry Monakhov ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", 19228a535f9SDmitry Monakhov io, inode->i_ino, io0, io1); 19328a535f9SDmitry Monakhov } 19428a535f9SDmitry Monakhov #endif 19528a535f9SDmitry Monakhov } 19628a535f9SDmitry Monakhov 19728a535f9SDmitry Monakhov /* Add the io_end to per-inode completed end_io list. */ 19897a851edSJan Kara static void ext4_add_complete_io(ext4_io_end_t *io_end) 19928a535f9SDmitry Monakhov { 20028a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(io_end->inode); 20178371a45SJan Kara struct ext4_sb_info *sbi = EXT4_SB(io_end->inode->i_sb); 20228a535f9SDmitry Monakhov struct workqueue_struct *wq; 20328a535f9SDmitry Monakhov unsigned long flags; 20428a535f9SDmitry Monakhov 2057b7a8665SChristoph Hellwig /* Only reserved conversions from writeback should enter here */ 2067b7a8665SChristoph Hellwig WARN_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); 20778371a45SJan Kara WARN_ON(!io_end->handle && sbi->s_journal); 20828a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 20978371a45SJan Kara wq = sbi->rsv_conversion_wq; 2102e8fa54eSJan Kara if (list_empty(&ei->i_rsv_conversion_list)) 2112e8fa54eSJan Kara queue_work(wq, &ei->i_rsv_conversion_work); 2122e8fa54eSJan Kara list_add_tail(&io_end->list, &ei->i_rsv_conversion_list); 21328a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 21428a535f9SDmitry Monakhov } 21528a535f9SDmitry Monakhov 2162e8fa54eSJan Kara static int ext4_do_flush_completed_IO(struct inode *inode, 2172e8fa54eSJan Kara struct list_head *head) 21828a535f9SDmitry Monakhov { 21928a535f9SDmitry Monakhov ext4_io_end_t *io; 220002bd7faSJan Kara struct list_head unwritten; 22128a535f9SDmitry Monakhov unsigned long flags; 22228a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(inode); 22328a535f9SDmitry Monakhov int err, ret = 0; 22428a535f9SDmitry Monakhov 22528a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 2262e8fa54eSJan Kara dump_completed_IO(inode, head); 2272e8fa54eSJan Kara list_replace_init(head, &unwritten); 22828a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 22928a535f9SDmitry Monakhov 23028a535f9SDmitry Monakhov while (!list_empty(&unwritten)) { 23128a535f9SDmitry Monakhov io = list_entry(unwritten.next, ext4_io_end_t, list); 23228a535f9SDmitry Monakhov BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); 23328a535f9SDmitry Monakhov list_del_init(&io->list); 23428a535f9SDmitry Monakhov 23528a535f9SDmitry Monakhov err = ext4_end_io(io); 23628a535f9SDmitry Monakhov if (unlikely(!ret && err)) 23728a535f9SDmitry Monakhov ret = err; 23828a535f9SDmitry Monakhov } 23928a535f9SDmitry Monakhov return ret; 24028a535f9SDmitry Monakhov } 24128a535f9SDmitry Monakhov 242bd2d0210STheodore Ts'o /* 2432e8fa54eSJan Kara * work on completed IO, to convert unwritten extents to extents 244bd2d0210STheodore Ts'o */ 2452e8fa54eSJan Kara void ext4_end_io_rsv_work(struct work_struct *work) 246bd2d0210STheodore Ts'o { 24784c17543SJan Kara struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info, 2482e8fa54eSJan Kara i_rsv_conversion_work); 2492e8fa54eSJan Kara ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_rsv_conversion_list); 2502e8fa54eSJan Kara } 2512e8fa54eSJan Kara 252bd2d0210STheodore Ts'o ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) 253bd2d0210STheodore Ts'o { 254b17b35ecSJesper Juhl ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); 255bd2d0210STheodore Ts'o if (io) { 256f7ad6d2eSTheodore Ts'o io->inode = inode; 257bd2d0210STheodore Ts'o INIT_LIST_HEAD(&io->list); 25897a851edSJan Kara atomic_set(&io->count, 1); 259bd2d0210STheodore Ts'o } 260bd2d0210STheodore Ts'o return io; 261bd2d0210STheodore Ts'o } 262bd2d0210STheodore Ts'o 26397a851edSJan Kara void ext4_put_io_end_defer(ext4_io_end_t *io_end) 26497a851edSJan Kara { 26597a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 26697a851edSJan Kara if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { 26797a851edSJan Kara ext4_release_io_end(io_end); 26897a851edSJan Kara return; 26997a851edSJan Kara } 27097a851edSJan Kara ext4_add_complete_io(io_end); 27197a851edSJan Kara } 27297a851edSJan Kara } 27397a851edSJan Kara 27497a851edSJan Kara int ext4_put_io_end(ext4_io_end_t *io_end) 27597a851edSJan Kara { 27697a851edSJan Kara int err = 0; 27797a851edSJan Kara 27897a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 27997a851edSJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 2806b523df4SJan Kara err = ext4_convert_unwritten_extents(io_end->handle, 2816b523df4SJan Kara io_end->inode, io_end->offset, 2826b523df4SJan Kara io_end->size); 2836b523df4SJan Kara io_end->handle = NULL; 28497a851edSJan Kara ext4_clear_io_unwritten_flag(io_end); 28597a851edSJan Kara } 28697a851edSJan Kara ext4_release_io_end(io_end); 28797a851edSJan Kara } 28897a851edSJan Kara return err; 28997a851edSJan Kara } 29097a851edSJan Kara 29197a851edSJan Kara ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end) 29297a851edSJan Kara { 29397a851edSJan Kara atomic_inc(&io_end->count); 29497a851edSJan Kara return io_end; 29597a851edSJan Kara } 29697a851edSJan Kara 297822dbba3SJan Kara /* BIO completion function for page writeback */ 2984246a0b6SChristoph Hellwig static void ext4_end_bio(struct bio *bio) 299bd2d0210STheodore Ts'o { 300bd2d0210STheodore Ts'o ext4_io_end_t *io_end = bio->bi_private; 3014f024f37SKent Overstreet sector_t bi_sector = bio->bi_iter.bi_sector; 302bd2d0210STheodore Ts'o 303bd2d0210STheodore Ts'o BUG_ON(!io_end); 304bd2d0210STheodore Ts'o bio->bi_end_io = NULL; 3050058f965SJan Kara 3064246a0b6SChristoph Hellwig if (bio->bi_error) { 307b0857d30SJan Kara struct inode *inode = io_end->inode; 308b0857d30SJan Kara 3099503c67cSMatthew Wilcox ext4_warning(inode->i_sb, "I/O error %d writing to inode %lu " 310f7ad6d2eSTheodore Ts'o "(offset %llu size %ld starting block %llu)", 3114246a0b6SChristoph Hellwig bio->bi_error, inode->i_ino, 312f7ad6d2eSTheodore Ts'o (unsigned long long) io_end->offset, 313f7ad6d2eSTheodore Ts'o (long) io_end->size, 314f7ad6d2eSTheodore Ts'o (unsigned long long) 315d50bdd5aSCurt Wohlgemuth bi_sector >> (inode->i_blkbits - 9)); 3164246a0b6SChristoph Hellwig mapping_set_error(inode->i_mapping, bio->bi_error); 317f7ad6d2eSTheodore Ts'o } 318822dbba3SJan Kara 319822dbba3SJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 320822dbba3SJan Kara /* 321822dbba3SJan Kara * Link bio into list hanging from io_end. We have to do it 322822dbba3SJan Kara * atomically as bio completions can be racing against each 323822dbba3SJan Kara * other. 324822dbba3SJan Kara */ 325822dbba3SJan Kara bio->bi_private = xchg(&io_end->bio, bio); 32697a851edSJan Kara ext4_put_io_end_defer(io_end); 327822dbba3SJan Kara } else { 328822dbba3SJan Kara /* 329822dbba3SJan Kara * Drop io_end reference early. Inode can get freed once 330822dbba3SJan Kara * we finish the bio. 331822dbba3SJan Kara */ 332822dbba3SJan Kara ext4_put_io_end_defer(io_end); 333822dbba3SJan Kara ext4_finish_bio(bio); 334822dbba3SJan Kara bio_put(bio); 335822dbba3SJan Kara } 336bd2d0210STheodore Ts'o } 337bd2d0210STheodore Ts'o 338bd2d0210STheodore Ts'o void ext4_io_submit(struct ext4_io_submit *io) 339bd2d0210STheodore Ts'o { 340bd2d0210STheodore Ts'o struct bio *bio = io->io_bio; 341bd2d0210STheodore Ts'o 342bd2d0210STheodore Ts'o if (bio) { 3435a33911fSTejun Heo int io_op = io->io_wbc->sync_mode == WB_SYNC_ALL ? 3445a33911fSTejun Heo WRITE_SYNC : WRITE; 345bd2d0210STheodore Ts'o bio_get(io->io_bio); 3465a33911fSTejun Heo submit_bio(io_op, io->io_bio); 347bd2d0210STheodore Ts'o bio_put(io->io_bio); 348bd2d0210STheodore Ts'o } 3497dc57615SPeter Huewe io->io_bio = NULL; 35097a851edSJan Kara } 35197a851edSJan Kara 35297a851edSJan Kara void ext4_io_submit_init(struct ext4_io_submit *io, 35397a851edSJan Kara struct writeback_control *wbc) 35497a851edSJan Kara { 3555a33911fSTejun Heo io->io_wbc = wbc; 35697a851edSJan Kara io->io_bio = NULL; 3577dc57615SPeter Huewe io->io_end = NULL; 358bd2d0210STheodore Ts'o } 359bd2d0210STheodore Ts'o 36097a851edSJan Kara static int io_submit_init_bio(struct ext4_io_submit *io, 361bd2d0210STheodore Ts'o struct buffer_head *bh) 362bd2d0210STheodore Ts'o { 363bd2d0210STheodore Ts'o struct bio *bio; 364bd2d0210STheodore Ts'o 365b54ffb73SKent Overstreet bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES); 366a1d8d9a7STheodore Ts'o if (!bio) 367a1d8d9a7STheodore Ts'o return -ENOMEM; 368001e4a87STejun Heo wbc_init_bio(io->io_wbc, bio); 3694f024f37SKent Overstreet bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); 370bd2d0210STheodore Ts'o bio->bi_bdev = bh->b_bdev; 371bd2d0210STheodore Ts'o bio->bi_end_io = ext4_end_bio; 37297a851edSJan Kara bio->bi_private = ext4_get_io_end(io->io_end); 373bd2d0210STheodore Ts'o io->io_bio = bio; 374bd2d0210STheodore Ts'o io->io_next_block = bh->b_blocknr; 375bd2d0210STheodore Ts'o return 0; 376bd2d0210STheodore Ts'o } 377bd2d0210STheodore Ts'o 378bd2d0210STheodore Ts'o static int io_submit_add_bh(struct ext4_io_submit *io, 379bd2d0210STheodore Ts'o struct inode *inode, 3802058f83aSMichael Halcrow struct page *page, 381bd2d0210STheodore Ts'o struct buffer_head *bh) 382bd2d0210STheodore Ts'o { 383bd2d0210STheodore Ts'o int ret; 384bd2d0210STheodore Ts'o 385bd2d0210STheodore Ts'o if (io->io_bio && bh->b_blocknr != io->io_next_block) { 386bd2d0210STheodore Ts'o submit_and_retry: 387bd2d0210STheodore Ts'o ext4_io_submit(io); 388bd2d0210STheodore Ts'o } 389bd2d0210STheodore Ts'o if (io->io_bio == NULL) { 39097a851edSJan Kara ret = io_submit_init_bio(io, bh); 391bd2d0210STheodore Ts'o if (ret) 392bd2d0210STheodore Ts'o return ret; 393bd2d0210STheodore Ts'o } 3942058f83aSMichael Halcrow ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh)); 395a549984bSTheodore Ts'o if (ret != bh->b_size) 396a549984bSTheodore Ts'o goto submit_and_retry; 397001e4a87STejun Heo wbc_account_io(io->io_wbc, page, bh->b_size); 39897a851edSJan Kara io->io_next_block++; 399bd2d0210STheodore Ts'o return 0; 400bd2d0210STheodore Ts'o } 401bd2d0210STheodore Ts'o 402bd2d0210STheodore Ts'o int ext4_bio_write_page(struct ext4_io_submit *io, 403bd2d0210STheodore Ts'o struct page *page, 404bd2d0210STheodore Ts'o int len, 4051c8349a1SNamjae Jeon struct writeback_control *wbc, 4061c8349a1SNamjae Jeon bool keep_towrite) 407bd2d0210STheodore Ts'o { 4082058f83aSMichael Halcrow struct page *data_page = NULL; 409bd2d0210STheodore Ts'o struct inode *inode = page->mapping->host; 4100058f965SJan Kara unsigned block_start, blocksize; 411bd2d0210STheodore Ts'o struct buffer_head *bh, *head; 412bd2d0210STheodore Ts'o int ret = 0; 4130058f965SJan Kara int nr_submitted = 0; 414937d7b84STheodore Ts'o int nr_to_submit = 0; 415bd2d0210STheodore Ts'o 416bd2d0210STheodore Ts'o blocksize = 1 << inode->i_blkbits; 417bd2d0210STheodore Ts'o 418d50bdd5aSCurt Wohlgemuth BUG_ON(!PageLocked(page)); 419bd2d0210STheodore Ts'o BUG_ON(PageWriteback(page)); 420bd2d0210STheodore Ts'o 4211c8349a1SNamjae Jeon if (keep_towrite) 4221c8349a1SNamjae Jeon set_page_writeback_keepwrite(page); 4231c8349a1SNamjae Jeon else 424a54aa761STheodore Ts'o set_page_writeback(page); 425a54aa761STheodore Ts'o ClearPageError(page); 426bd2d0210STheodore Ts'o 4270058f965SJan Kara /* 428f8409abdSLinus Torvalds * Comments copied from block_write_full_page: 429eeece469SJan Kara * 430eeece469SJan Kara * The page straddles i_size. It must be zeroed out on each and every 431eeece469SJan Kara * writepage invocation because it may be mmapped. "A file is mapped 432eeece469SJan Kara * in multiples of the page size. For a file that is not a multiple of 433eeece469SJan Kara * the page size, the remaining memory is zeroed when mapped, and 434eeece469SJan Kara * writes to that region are not written out to the file." 435eeece469SJan Kara */ 436eeece469SJan Kara if (len < PAGE_CACHE_SIZE) 437eeece469SJan Kara zero_user_segment(page, len, PAGE_CACHE_SIZE); 438eeece469SJan Kara /* 4390058f965SJan Kara * In the first loop we prepare and mark buffers to submit. We have to 4400058f965SJan Kara * mark all buffers in the page before submitting so that 4410058f965SJan Kara * end_page_writeback() cannot be called from ext4_bio_end_io() when IO 4420058f965SJan Kara * on the first buffer finishes and we are still working on submitting 4430058f965SJan Kara * the second buffer. 4440058f965SJan Kara */ 4450058f965SJan Kara bh = head = page_buffers(page); 4460058f965SJan Kara do { 4470058f965SJan Kara block_start = bh_offset(bh); 448bd2d0210STheodore Ts'o if (block_start >= len) { 449bd2d0210STheodore Ts'o clear_buffer_dirty(bh); 450bd2d0210STheodore Ts'o set_buffer_uptodate(bh); 451bd2d0210STheodore Ts'o continue; 452bd2d0210STheodore Ts'o } 4538a850c3fSJan Kara if (!buffer_dirty(bh) || buffer_delay(bh) || 4548a850c3fSJan Kara !buffer_mapped(bh) || buffer_unwritten(bh)) { 4558a850c3fSJan Kara /* A hole? We can safely clear the dirty bit */ 4568a850c3fSJan Kara if (!buffer_mapped(bh)) 4578a850c3fSJan Kara clear_buffer_dirty(bh); 4588a850c3fSJan Kara if (io->io_bio) 4598a850c3fSJan Kara ext4_io_submit(io); 4608a850c3fSJan Kara continue; 4618a850c3fSJan Kara } 4620058f965SJan Kara if (buffer_new(bh)) { 4630058f965SJan Kara clear_buffer_new(bh); 4640058f965SJan Kara unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 4650058f965SJan Kara } 4660058f965SJan Kara set_buffer_async_write(bh); 467937d7b84STheodore Ts'o nr_to_submit++; 4680058f965SJan Kara } while ((bh = bh->b_this_page) != head); 4690058f965SJan Kara 4700058f965SJan Kara bh = head = page_buffers(page); 4712058f83aSMichael Halcrow 472937d7b84STheodore Ts'o if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) && 473937d7b84STheodore Ts'o nr_to_submit) { 474c9af28fdSTheodore Ts'o gfp_t gfp_flags = GFP_NOFS; 475c9af28fdSTheodore Ts'o 476c9af28fdSTheodore Ts'o retry_encrypt: 477c9af28fdSTheodore Ts'o data_page = ext4_encrypt(inode, page, gfp_flags); 4782058f83aSMichael Halcrow if (IS_ERR(data_page)) { 4792058f83aSMichael Halcrow ret = PTR_ERR(data_page); 480*4762cc3fSDan Carpenter if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) { 481c9af28fdSTheodore Ts'o if (io->io_bio) { 482c9af28fdSTheodore Ts'o ext4_io_submit(io); 483c9af28fdSTheodore Ts'o congestion_wait(BLK_RW_ASYNC, HZ/50); 484c9af28fdSTheodore Ts'o } 485c9af28fdSTheodore Ts'o gfp_flags |= __GFP_NOFAIL; 486c9af28fdSTheodore Ts'o goto retry_encrypt; 487c9af28fdSTheodore Ts'o } 4882058f83aSMichael Halcrow data_page = NULL; 4892058f83aSMichael Halcrow goto out; 4902058f83aSMichael Halcrow } 4912058f83aSMichael Halcrow } 4922058f83aSMichael Halcrow 4932058f83aSMichael Halcrow /* Now submit buffers to write */ 4940058f965SJan Kara do { 4950058f965SJan Kara if (!buffer_async_write(bh)) 4960058f965SJan Kara continue; 4972058f83aSMichael Halcrow ret = io_submit_add_bh(io, inode, 4982058f83aSMichael Halcrow data_page ? data_page : page, bh); 499bd2d0210STheodore Ts'o if (ret) { 500bd2d0210STheodore Ts'o /* 501bd2d0210STheodore Ts'o * We only get here on ENOMEM. Not much else 502bd2d0210STheodore Ts'o * we can do but mark the page as dirty, and 503bd2d0210STheodore Ts'o * better luck next time. 504bd2d0210STheodore Ts'o */ 505bd2d0210STheodore Ts'o break; 506bd2d0210STheodore Ts'o } 5070058f965SJan Kara nr_submitted++; 5081ae48a63SJan Kara clear_buffer_dirty(bh); 5090058f965SJan Kara } while ((bh = bh->b_this_page) != head); 5100058f965SJan Kara 5110058f965SJan Kara /* Error stopped previous loop? Clean up buffers... */ 5120058f965SJan Kara if (ret) { 5132058f83aSMichael Halcrow out: 5142058f83aSMichael Halcrow if (data_page) 5152058f83aSMichael Halcrow ext4_restore_control_page(data_page); 5162058f83aSMichael Halcrow printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); 5172058f83aSMichael Halcrow redirty_page_for_writepage(wbc, page); 5180058f965SJan Kara do { 5190058f965SJan Kara clear_buffer_async_write(bh); 5200058f965SJan Kara bh = bh->b_this_page; 5210058f965SJan Kara } while (bh != head); 522bd2d0210STheodore Ts'o } 523bd2d0210STheodore Ts'o unlock_page(page); 5240058f965SJan Kara /* Nothing submitted - we have to end page writeback */ 5250058f965SJan Kara if (!nr_submitted) 5260058f965SJan Kara end_page_writeback(page); 527bd2d0210STheodore Ts'o return ret; 528bd2d0210STheodore Ts'o } 529